Spatially limited regions inside a space typically serve various purposes regarding sound reproduction. A field of interest in the audio industry is the ability to reproduce multiple regions of different sound material simultaneously inside an open room. This is desired to be obtained without the use of physical separation or the use of headphones, and is herein referred to as “establishing sound zones”. A sound zone is a room or area in which sound is distributed. More specifically, arrays of loudspeakers with adequate preprocessing of the audio signals to be reproduced are of concern, in which different sound material is reproduced in predefined zones without interfering signals from adjacent ones. In order to realize sound zones, it is necessary to adjust the response of multiple sound sources to approximate the desired sound field in the reproduction region. A large variety of concepts concerning sound field control, have been published, with different degrees of applicability to the generation of sound zones.